Strong Supporting Material Increases Credibility

• Review your personal knowledge.

• Interview experts.

When referring to interviews in a speech, identify the

interviewee and describe her or his expertise.

• Do library and on-line research.

• Conduct surveys.

Libraries provide rich information on speech topics.

• Reference works direct speakers to key sources of information on specific topics.

• Indexes summarize publications by area and provide information on authors.

• Databases are stores of information that can be accessed from computer terminals. Library databases include popular and

academic publications and news services.

Infotrac is a fully searchable on-line database that gives access to the complete articles

published in over 600 periodicals.

http://www.infotrac-college.com

Search engines such as Yahoo allow you to do subject searches but need to be evaluated and used cautiously.

Evaluating On-Line Sources 1. Can you verify the material independently?2. Does the source of material have the

experience, position, or other credentials to be an authority?

3. Does the source of the material have any vested interest in making the claim or presenting the alleged information?

4. Is the source an expert in the area of the material?

5. If you decide on-line material is sound, you should cite it in your bibliography as well as your text.

www.ciolek.com/WWWVL-InfoQuality.html

Surveys are means of gathering information about people’s opinions,

actions, beliefs, preferences, and so forth.

• Surveys are useful when there is little or no published information on a topic.

• Surveys are useful when a speaker wants to find out what specific listeners know, believe, and think about a topic.

Guidelines for Constructing Surveys1. Respondents should be chosen to reflect the

population.2. There should be eight respondents for each survey

item.3. Respondents should be qualified to answer the

questions.4. Questions should be worded to avoid bias.5. Each question should focus on only one issue.6. Questions should allow for all possible responses.7. Questions should rely on language that will be

clear to respondents.8. Avoid negative language in survey items, because

it tends to be confusing.

Evidence

• Evidence is material used to support claims a speaker makes. Makes ideas more clear, compelling, and

dramatic Strengthens a speaker’s opinions Demonstrates ideas Allows speaker’s to achieve derived

credibility

Observe the methods used by the speaker to cite sources in the following section from a speech.

Five Types of Evidence

• Statistics

• Examples

• Analogies

• Quotations

• Visual aids

Should be adapted to the attitudes, values, and knowledge of listeners.

Is Evidence Ethical and Effective?• Is there enough evidence to support a claim?• Is the evidence accurately presented—quotations

are verbatim, nothing is taken out of context?• Does the evidence relate directly to the claim it is

intended to support?• Is the evidence appropriately timely—statistics,

quotations, examples, comparisons, current or appropriate for the time being discussed?

• Is the evidence free of biases such as vested interest?

Statistics• Numbers that summarize many individual cases

or that demonstrate relationships among phenomena Should be limited in a speech Round off numbers so listeners can understand and

retain them

• Select statistics that are not dated.

• Example: “North Americans make up only 6% of the world’s

population, yet they consume 40% to 60% of the planet’s resources.

Examples• Instances used to make a point, dramatize

an idea, or personalize information Undetailed examples are quick reference. Detailed examples provide more in-depth

descriptions of instances. Hypothetical examples are created instances

(what if situations) and should be identified clearly as hypothetical, not factual.

Stories are extended examples in which a great deal of information is woven into a coherent account.

Comparisons

• State associations between two things that are similar in important respects Similes are direct comparisons that use the

word like or as to link the phenomena being compared.• “A teacher is like a guide.”

Analogies are metaphors that state one thing is another thing.• “Life is a grand adventure.”

Quotations

• Exact citations of statements made by others Quote individuals listeners know and respect Cite individuals who are qualified to speak on the

issue for which they are being quoted Should be checked for absolute accuracy and

should not be taken out of context Should come from unbiased sources Avoid the “halo effect” which involves assuming

that an expert in one area is also an expert in other areas

• Charts

• Graphs

• Photographs

• Models

• Transparencies

• Computer graphics

• Physical objects

Visual Aids Increase Listeners’ Understanding and Retention

of Ideas

TransparencySheet of clear acetate shown on an overhead projector:

The correct way to wear a seat belt is discussed.

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Model – a facsimile of an object you can’t easily use in your speech.

A model is used to discuss the molecule tylenol.

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A picture on a transparency is used to describe a volcano.

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Computer-aided graphics are used to discuss aero dynamics in a speech.

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Computer-aided graphics can be used to create a bar graph that then can be

projected or made into a transparency.

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Guideline for Deciding How Many Visuals to Use in a Speech

Length of speech 2

+ 1 = maximum number of visuals

- Cheryl Hamilton (1996)

Guidelines for Using Computer-Aided Slides in a Speech

1. Each slide should focus on a single concept—use phrases or key words.

2. Font should be large enough to be read by listeners.

• 36 for main points• Supporting points in 18 to 24• Text should not be smaller than 18

3. Typeface should be clean and clear.

Guidelines for Using Slides in a Speech

4. Mix upper and lower case letters. ALL CAPITAL LETTERS ARE HARD TO READ.

5. Use art to provide visual relief from text and enhance interest.

6. Use one design consistently.

7. Select a color scheme that is visually strong but not overpowering.

8. Use special effects sparingly.

Guidelines for Using Slides in a Speech

9. Use visual highlighting sparingly.

10. Give credit to those who created any material you use.

11. Don’t sacrifice content for flashy visuals.• Your content is your first priority. Visual

aids, including computerized ones should enhance your content, not substitute for it.

12. Make slides light and bright enough that you do not have to darken the room fully.